From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 98923C433DF for ; Wed, 12 Aug 2020 16:38:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7098220771 for ; Wed, 12 Aug 2020 16:38:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726705AbgHLQi0 (ORCPT ); Wed, 12 Aug 2020 12:38:26 -0400 Received: from mga12.intel.com ([192.55.52.136]:32724 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725872AbgHLQiZ (ORCPT ); Wed, 12 Aug 2020 12:38:25 -0400 IronPort-SDR: ZUPIy3kd2tV02Mk48MYVnqpMzHRJYWhF+5HgEBp3ur+8py+AsfVQiBUppmTCRDKADZIT+QoI62 RLrcy7iVRLbQ== X-IronPort-AV: E=McAfee;i="6000,8403,9711"; a="133535379" X-IronPort-AV: E=Sophos;i="5.76,304,1592895600"; d="scan'208";a="133535379" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2020 09:38:25 -0700 IronPort-SDR: Ot9t+RPuVM04ujHrIjA/yFHnd3j6C8ApNIb/yJnjh59NLl4QSLTBu2gl/mqJMJI5JAajkcvWiG vTaGQIgcteXQ== X-IronPort-AV: E=Sophos;i="5.76,304,1592895600"; d="scan'208";a="495572467" Received: from mbharapa-mobl.amr.corp.intel.com (HELO [10.212.31.62]) ([10.212.31.62]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Aug 2020 09:38:23 -0700 Subject: Re: [PATCH v3 2/2] ASoC: Intel: Add period size constraint on strago board To: "Lu, Brent" , Takashi Iwai Cc: Yu-Hsuan Hsu , Guennadi Liakhovetski , "alsa-devel@alsa-project.org" , Andy Shevchenko , Kuninori Morimoto , Kai Vehmanen , "linux-kernel@vger.kernel.org" , "Rojewski, Cezary" , Jie Yang , Takashi Iwai , Liam Girdwood , Sam McNally , Mark Brown , Ranjani Sridharan , Daniel Stuart , "yuhsuan@google.com" , Damian van Soelen References: <3f3baf5e-f73d-9cd6-cbfb-36746071e126@linux.intel.com> <20200811145353.GG6967@sirena.org.uk> <20200811172209.GM6967@sirena.org.uk> From: Pierre-Louis Bossart Message-ID: <0714b222-d3fc-5744-1147-bfac7df2651e@linux.intel.com> Date: Wed, 12 Aug 2020 11:38:22 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/12/20 11:08 AM, Lu, Brent wrote: >>> >>> I also wonder what's really missing, too :) >>> >>> BTW, I took a look back at the thread, and CRAS seems using a very >>> large buffer, namely: >>> [ 52.434791] sound pcmC1D0p: PERIOD_SIZE [240:240] >>> [ 52.434802] sound pcmC1D0p: BUFFER_SIZE [204480:204480] >> >> yes, that's 852 periods and 4.260 seconds. Never seen such values :-) > > CRAS calls snd_pcm_hw_params_set_buffer_size_max() to use as large > buffer as possible. So the period size is an arbitrary number in different > platforms. Atom SST platform happens to be 256, and CML SOF platform > is 1056 for example. ok, but earlier in this thread it was mentioned that values such as 432 are not suitable. the statement above seems to mean the period actual value is a "don't care", so I don't quite see why this specific patch2 restricting the value to 240 is necessary. Patch1 is needed for sure, Patch2 is where Takashi and I are not convinced.